What are the optimal dose parameters for heating a superficial tendon?

• A. 3 MHz, 0.8-1 W/cm2, 4-5 min
• B. 3 MHz, 1.5 W/cm2, 7 min
• C. 1 MHz, 0.8-1 W/cm2, 6 min
• D. 3 MHz, 0.2 W/cm2, 2 min

Answer: (A)

When heating a structure close to the surface, you want energy delivered mainly to the near-surface tissues rather than deeper layers. A higher ultrasound frequency, like 3 MHz, confines the energy near the skin, making it appropriate for a superficial tendon. The dose should be enough to raise temperature into a therapeutic range but not so high as to risk skin or subdermal overheating, so an intensity around 0.8–1.0 W/cm² is ideal. A treatment time of about 4–5 minutes Usually provides a meaningful temperature rise in superficial structures without excessive exposure.

The other options either use a frequency that would penetrate too deeply (1 MHz), or an intensity that’s too high for superficial heating (1.5 W/cm²), or an intensity too low or a duration that’s insufficient to achieve the desired heat in a superficial tendon (0.2 W/cm² or only 2 minutes).